1. Ordinal scales and foundations of misinference;Merbitz;Arch Phys Med Rehabil,1989
2. Observations are always ordinal; measurements, however, must be interval;Wright;Arch Phys Med Rehabil,1989
3. Rasch analysis of functional assessment scale: an example using pain behaviors;McArthur;Arch Phys Med Rehabil,1991
4. Applying psychometric criteria to functional assessment in medical rehabilitation: II. defining interval measures;Silverstein;Arch Phys Med Rehabil,1992
5. Functional Independence Measure;Forer,1987